The characteristics of disinfection by-product (DBP) formation in the distribution system of Hiroshima City were investigated. Then a model was developed for predicting DBPs based on multiple regression analysis. Potassium permanganate consumption value (KMnO4), free chlorine residual concentration (Cl2), pH, water temperature (WT) and residence time (RT) were confirmed to have an influence on DBP formation in the distribution system and used as independent variables.

The correlation coefficients between the logarithmic values of the predicted DBPs and those of the observed DBPs were higher than 0.7. In addition, the seasonal change patterns of the predicted DBPs were very similar to those observed in some DBPs. The model is helpful for managing the DBPs in water distribution systems.